Situations arise where a new section of a borehole is to be perforated, fracked, acidized or stimulated or otherwise treated and produced but before that happens access to an existing formation needs to be isolated if the casing where the new completion is to take place is to be pressure tested to levels that might do damage to an existing formation below. This can happen if there is a shoe at the borehole bottom that has had displacement fluid pumped through it to displace cement into an annulus. This is called a wet shoe and is done for ease of later access to the borehole bottom when later making more hole. In other situations there may still be an intent to continue production from existing perforations that are further downhole after the new completion is concluded. In still other circumstances there may be nearby injection wells that can flow over into existing perforations and the need is to isolate the surrounding injection wells from the zone to be pressure tested.
Beyond these needs is the need to be able to start and finish the new completion as soon as possible after a successful pressure test. Since there is a high probability that the tested zone is in a horizontal section of the borehole, there will be a need to deliver completion equipment to the desired location with flow. This is because wireline is not effective to deliver tools in horizontal runs without flow. Accordingly the present invention allows for quick re-establishing of flow with a pressure sensitive member in a passage through a wireline run and set bridge plug. Once the pressure test is over above the set bridge plug and the wireline is removed, application of pressure or other techniques removes a barrier so that completion equipment can be delivered to the tested zone with flow. The bridge plug can later be milled out or left in the wellbore dependent on the application and location of the bridge plug.
Various devices have used removable barriers for other purposes such as U.S. Pat. No. 6,206,094 item 108; U.S. Pat. No. 5,615,741 item 172; U.S. Pat. No. 6,634,428 item 56; U.S. Pat. No. 4,221,264 item 64; U.S. Pat. No. 7,845,400 item 14; U.S. Pat. No. 8,201,634 item 250 and US 2012/0111566 item 20. Some designs use temporary plugs that dissolve or disintegrate as shown in U.S. Pat. No. 5,479,986; US 2011/0048743 and U.S. Pat. No. 8,276,670. These rupture disc designs do not relate to the specific application of the present invention regarding the use of pressure testing followed by a need to rapidly commence additional completion tasks. The temporary plugs made of sand that get severed or others that need to dissolve all take time to open a flow passage and some of those prior designs also left a potential debris issue in the borehole that could impede subsequent operations or cause a need for a milling operation that would invite further delay in subsequent completion work.
Those skilled in the art will better understand aspects of the present invention from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.